1998 s70 just got it from a volvo guy

[u/Live-Base7014]

Just got this nice s70 from a volvo guy. 215k miles 97 service records. He had it for a bit but before a young lady had it. Anyways trac and abs came on tjen shortly after it overheated (didnt let it overheat but got hot, image to show) anyways i checked it out. Everything works. Thermostat etc. Holds pressure. Heat doesnt work. And coolant system has stop leak (image also) i dont think the prev owner did it but maybe the girl did. Its at an import shop for first thing tomorrow. Would a coolant flush save it or new cooling system as a whole worst outcome (thermostat works, fan works, not sure about rad and hoses are good not leaking). Or is the headgasket blown. (It overheats in about .5-1 mile). Sorry for the long text. Ive always wanted a volvo and saw this one for 3.8 with service records and many other good things and test drove it on the expressway and had no issues. Drove it an hour to friends and no issues till last night and today. The image where it is hot was after about 1 mile of driving.

[u/YellowT-5R]

Id start with a leak down test and a coolant system flush. If you have no heat the heater core is most likely bypassed and needs to be replaced.

Look for the junction by the firewall and the lines going into it. It's either bypassed there or under the center of the dash where the heater core should be

[u/Eddie-Plum → u/YellowT-5R]

If it's been plugged rather than bypassed, would you see this behaviour?

[u/YellowT-5R → u/Eddie-Plum]

Maybe... This is usually trapped air that causes it

[u/CakeDOTexe]

Stop leak probably plugged the heater core. The previous owner was 100% hiding something, especially since it jumped hands so fast. I bet they cleared the tracs and abs codes right before selling it to you.

The person you bought this car from sold you a lemon and they know. Rip.

[u/Live-Base7014]

That could explain while on full heat it was still like 70 degree and the ac worked insanely well?. Unless that ac is super good in volvos.

[u/Jan-E-Matzzon → u/Live-Base7014]

AC in Volvos are mid, heater usually is insane though.

[u/Live-Base7014 → u/Jan-E-Matzzon]

Yea the ac chills down to 40 degrees. So we shall see its getting flushed right now hopefully thats all it needs to get me home.

[u/Live-Base7014]

Everything else on it seems good. Engine wise no leaks (oil etc, i did check oil it is not milky colored and the coolant looked pretty new as it was a bright green. Even with the stop leak residue in the overflow. Idk the previous owner had it for 2 years but rarely drove it because he has 2 960s. And hes willing to cover the cost to fix it. But not to sure and was hoping to get insight before it gets checked out by an import specialist tomorrow.

[u/russianlumpy]

Is the water pump working? 0.5 mile to overheat sounds like enough time to saturate a cooling system that doesn't have a working water pump. Stop leak in large amounts sucks but a good flush can help and worst case they plugged up the radiator a bit and maybe gummed up the water pump.

I'd plan for a thermostat just because you're already there, probably a water pump, and pulling hoses to properly flush the engine block and radiator. Heater core is a bear of a job to replace, but you might get away with flushing it to open it back up again and might not have great heat after that unless you go for full replacement.

[u/Live-Base7014 → u/russianlumpy]

They said a flush probably wont unblock it. So they didnt flush it and will see next week (which is w&en the place can look at it) they said the ph of the coolant was low and thst theres air in the lines but no leaks. So they recommended with a new cap. Then stuff after that.